The present invention is generally directed to impingement flow cooling of electronic modules and chips. More particularly, the present invention is directed to a planar configuration of supply and exhaust channels which permits tunable cooling and which furthermore permits chips and modules to be packed densely in adjacent or nearly adjacent patterns.
Modern electronic circuit chips are consuming ever larger mounts of electrical power. Because of the desire to operate these circuits at increased frequencies, there is a concomitant increase in the power dissipated by these chips. Similarly, because of the same desire for speed and also because of the desire to achieve physical compactness, more and more circuits are being placed on electronic chip devices. Accordingly, it is seen that there is an ever increasing rise in the power dissipation associated with these chips, as measured in watts per square centimeter (power per unit area). Accordingly, it is seen that there is a decided need to be able to cool not just individual chips but also assemblies of electronic chips.
These electronic circuit chips may be disposed directly on a printed circuit board and may from time to time employ heat sink devices which assist in removal of heat from the electronic chip. Additionally, it is noted that electronic chips may be disposed on intermediate substrates to produce what is typically referred to as multi-chip modules. Whether disposed on an intermediate substrate or directly on a circuit board, the cooling problems associated with assemblies of these electronic devices remain the same. The discussions herein therefore with respect to integrated circuit chips are also directly applicable to an alternate embodiment employing multi-chip modules.
As indicated above, modern electronic circuit chips and their associated high-density packaging configurations not only require significant cooling, but, in keeping with the desire for overall compactness, it is desirable to be able to provide a cooling assembly or cooling unit which likewise takes up as low a volume as possible and which is disposable in the same overall planar configuration employed for circuit boards and/or circuit modules.
Additionally, it is noted that a greater variety of chips are disposed on printed circuit boards or on multi-chip module substrates, there can be a wide disparity in the power/cooling requirements for these chips. In particular, it is noted that certain chips might in fact run hot while others may run decidedly cooler because of the large variety of chip functions which must coexist on a single backplane. Accordingly, it is therefore desirable to provide a readily manufacturable and usable mechanism for tuning a cooling system so as to provide maximum cooling for those chips having the greatest cooling needs in terms of thermal power density.
As an illustration of the great challenges associated with cooling electronic devices, it is noted that it is anticipated that by the year 2000 the thermal power density associated with operating electronic circuit chips, as measured in watts per square centimeter, will have substantially increased. Accordingly, it is seen that the cooling of electronic chip devices is a non-trivial problem.